During the process of manufacturing an automotive vehicle, it is known to assemble the wheels of the vehicle on a dedicated production facility, independently of the remainder of the vehicle. This makes it possible in particular to optimize wheel fitting times, to improve the reliability of quality control checks and to reduce costs.
In a known manner, a wheel assembly facility comprises several assembly lines disposed side by side and which each comprise a robot of press type allowing the tires to be fitted on the rims.
In order to be able to verify the value of certain parameters of a wheel once the latter has been assembled, such as for example the pressure or the internal temperature of the tires, it is known to fit a measurement module, a so-called “TPMS” (“Tire Pressure Measurement System”), inside the tire or on the rim before assembling the wheel.
This measurement module comprises one or more sensors, for example for measuring pressure, temperature or acceleration, and is configured at one and the same time to receive request messages and, in return, to dispatch response messages comprising the values of parameters measured by the sensors as well as the identifier of the measurement module.
In order to allow the checking of these parameters on the assembly line, it is known to use a diagnostic module which will communicate with the measurement module of each of the wheels assembled on the line, in particular so as to collect its identifier and to associate (or match) said identifier with the wheel, for example by using a barcode stuck on the tire.
Each assembly line comprises its own diagnostic module which emits signals comprising a request message destined in turn for each measurement module of a wheel assembled on said line. These signals are emitted in a known manner on a low-frequency communication link, also called LF (for “Low-Frequency”) link, this type of link making it possible in particular to check the distance and the direction of the signal so as to ensure that a diagnostic module interrogates only a single measurement module, namely the measurement module closest to the diagnostic module.
A request message comprises in a known manner a code making it possible to request a predefined list of parameters, in particular the identifier of the measurement module, for which the diagnostic module wishes to obtain values. The measurement module responds to the diagnostic module by dispatching a signal comprising a response message comprising the values of the parameters indicated by the code in the request message. This signal is emitted in a known manner on a radiofrequency communication link, also called RF (for “Radio-Frequency”) link, in particular so as to avoid using the same range of frequencies for emission and for reception and to reduce costs, a radiofrequency emission device being less expensive in terms of energy and therefore in terms of maintenance than a low-frequency emission device.
However, in contradistinction to a request message emitted on a low-frequency communication link, a response message emitted by a measurement module on a radiofrequency communication link could be received by a plurality of diagnostic modules.
Thus, each assembly line possessing its own diagnostic module and each measurement module using the same range of radiofrequencies, a response message dispatched by a measurement module of a first assembly line may be received by the diagnostic module of a neighboring second assembly line.
Moreover, each measurement module can dispatch information messages without having received any request message beforehand, for example following periodic measurements of pressure or of acceleration or when an event occurs on the tire (leak, rolling, etc.). These information messages are characteristic of the standard mode of operation of the measurement module when it is fitted in a wheel which is itself fitted on a vehicle. However, these information messages, in particular the periodic information messages, may be emitted when the measurement module is fitted in a wheel disposed on an assembly line.
Hence, when a diagnostic module receives a message, it is not able to determine whether this message is a response message in response to a request that it has dispatched or a response message intended for another diagnostic module or else an information message.